Several recent studies show that the lungs infected with Pseudomonas aeruginosa are often co-colonised by oral bacteria including black-pigmenting anaerobic (BPA) Porphyromonas species. The BPAs have an absolute haem requirement and their presence in the infected lung indicates that sufficient haem, a virulence up-regulator in BPAs, must be present to support growth. Haemoglobin from micro-blee...

INTRODUCTION Porphyromonas gingivalis is considered as a major etiological agent in the onset and progression of chronic destructive periodontitis. Porphyromonus gingivalis fimA type has been correlated to the virulence potential of the strain; therefore this gene could be involved in the ability of P. gingivalis to reach blood stream. OBJECTIVE The classifications of P. gingivalis fimA types...

To characterize the roles of Porphyromonas gingivalis and its components in disease processes, we investigated the cytokine profiles induced by live P. gingivalis, its lipopolysaccharide (LPS), and its major fimbrial protein, fimbrillin (FimA). A cytokine antibody array revealed that human monocyte-derived macrophages were induced to produce chemokines (e.g., monocyte chemoattractant protein 1,...

Porphyromonas gingivalis, an oral bacterium, might play a role in the pathogenesis or progression of adult periodontitis. In this study, we isolated from P. gingivalis a putative glycosyltransferase gene, designated gtfA, which had a consensus domain for glycosyltransferase in its N terminus. GtfA consisted of 248 amino acids and its predicted molecular mass was 28 kDa; however, as the molecula...

Porphyromonas gingivalis is a Gram-negative obligately anaerobic bacterium associated with several forms of periodontal disease, most closely with chronic periodontitis. Previous studies demonstrated that OxyR plays an important role in the aerotolerance of P. gingivalis by upregulating the expression of oxidative-stress genes. Increases in oxygen tension and in H(2)O(2) both induce activation ...

A consequence of oxidative stress is DNA damage. The survival of Porphyromonas gingivalis in the inflammatory microenvironment of the periodontal pocket requires an ability to overcome oxidative stress caused by reactive oxygen species (ROS). 8-oxo-7,8-dihydroguanine (8-oxoG) is typical of oxidative damage induced by ROS. There is no information on the presence of 8-oxoG in P. gingivalis under ...

BACKGROUND Periodontitis is recognized as a complex polymicrobial disease, however, the impact of the bacterial interactions among the 700-1,000 different species of the oral microbiota remains poorly understood. We conducted an in vitro screen for oral bacteria that mitigate selected virulence phenotypes of the important periodontal pathogen, Porphyromonas gingivalis. METHOD We isolated and ...

Periodontitis is defined as inflammation affecting the supporting tissue of teeth. Periodontal pathogens initiate the disease and induce inflammatory host response. Hypoxia may accelerate the process by producing pro-inflammatory factors. The aim of this study is to investigate the effect of Porphyromonas gingivalis (P. gingivalis) lipopolysaccharides (LPS) and Escherichia coli (E. coli) LPS in...

Porphyromonas gingivalis, the causative agent of adult periodontitis, must maintain nitric oxide (NO) homeostasis and surmount nitric oxide stress from host immune responses or other oral bacteria to survive in the periodontal pocket. To determine the involvement of a putative hydroxylamine reductase (PG0893) and a putative nitrite reductase-related protein (PG2213) in P. gingivalis W83 NO stre...

Porphyromonas gingivalis lipopolysaccharide (LPS) and its bioactive center, lipid A, are known to exhibit very low endotoxic activities and activate LPS-hyporesponsive C3H/HeJ mice that have a point mutation in the cytoplasmic portion of Toll-like receptor (TLR) 4, in contrast to classical enterobacterial LPS and their lipid A. In the present study, we attempted to determine which TLR mediates ...